Datasheet

LNBH23 LNBH23 software description
Doc ID 13356 Rev 8 17/32
X = don't care
All values are typical unless otherwise specified
Valid with TTX pin floating or to GND
7.4 Diagnostic received data (I²C read mode)
LNBH23 can provide to the MCU Master a copy of the diagnostic system register
information via I²C bus in read mode. The read mode is master activated by sending the
chip address with R/W bit set to 1. At the following master generated clocks bits, LNBH23
issues a byte on the SDA data bus line (MSB transmitted first). At the ninth clock bit the
master can:
● Acknowledge the reception, starting in this way the transmission of another byte from
the LNBH23
● No acknowledge, stopping the read mode communication
Three bits of the register are read back as a copy of the corresponding write output voltage
register status (LLC, VSEL, EN), while, the other five bits convey diagnostic information
about the over-temperature (OTF), output voltage level (VMON), output over-load (OLF),
Minimum output current presence (IMON) and 22 kHz tone (TMON). In normal operation the
diagnostic bits are set to zero, while, if a failure is occurring, the corresponding bit is set to
one. At start-up all the bits are reset to zero.
Table 6. Truth table
PCL TTX TEN LLC VSEL EN ITEST AUX Function
00010V
oRX
= 13.4V, V
UP
=14.15V, (V
UP
-V
oRX
=0.75V)
00110V
oRX
= 18.5V, V
UP
=19.25V, (V
UP
-V
oRX
=0.75V)
01010V
oRX
= 14.4V, V
UP
=15.15V, (V
UP
-V
oRX
=0.75V)
01110V
oRX
= 19.5V, V
UP
=20.25V, (V
UP
-V
oRX
=0.75V)
XX1X1V
oRX
= 22V, V
UP
=22.75V, (V
UP
-V
oRX
=0.75V)
0 1 22 kHz controlled by DSQIN pin (only if TTX=1)
1 1 1 22 kHz tone output is always activated
01
V
oRX
output is ON, V
oTX
Tone generator output is
OFF
11V
oRX
output is ON, V
oTX
Tone generator output is ON
0 1 Pulsed (Dynamic) current limiting is selected
1 1 Static current limiting is selected
XX10
Minimum output current diagnostic threshold = 6mA
typ.
XX11
Minimum output current diagnostic threshold = 12mA
typ.
X X X X X 0 X X Power block disabled